title: Heat-treated Saccharomyces cerevisiae for antimony speciation and antimony(III) preconcentration in water samples.
abstract: An analytical method was developed for antimony speciation and antimony(III) preconcentration in water samples. The method is based on the selective retention of Sb(III) by modified Saccharomyces cerevisiae in the presence of Sb(V). Heat, caustic and solvent pretreatments of the biomass were investigated to improve the kinetics and thermodynamics of Sb(III) uptake process at room temperature. Heating for 30 min at 80 degrees C was defined as the optimal treatment. Antimony accumulation by the cells was independent of pH (5-10) and ionic strength (0.01-0.1 mol L(-1)). 140 mg of yeast and 2h of contact were necessary to ensure quantitative sequestration of Sb(III) up to 750 microg L(-1). In these conditions, Sb(V) was not retained. Sb(V) was quantified in sorption supernatant by inductively coupled plasma mass spectrometry (ICP-MS) or inductively coupled plasma optical emission spectrometry (ICP-OES). Sb(III) was determined after elution with 40 mmol L(-1) thioglycolic acid at pH 10. A preconcentration factor close to nine was achieved for Sb(III) when 100mL of sample was processed. After preconcentration, the detection limits for Sb(III) and Sb(V) were 2 and 5 ng L(-1), respectively, using ICP-MS, 7 and 0.9 microg L(-1) using ICP-OES. The proposed method was successfully applied to the determination of Sb(III) and Sb(V) in spiked river and mineral water samples. The relative standard deviations (n=3) were in the 2-5% range at the tenth microg L(-1) level and less than 10% at the lowest Sb(III) and Sb(V) tested concentration (0.1 microg L(-1)). Corrected recoveries were in all cases close to 100%.
authors.affiliation: Université de Lyon, Lyon1, Laboratoire des Sciences Analytiques, CNRS UMR 5180, bât CPE, 43, boulevard du 11 novembre 1918, 69622 Villeurbanne cédex, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Marcellino
authors.forename: Hossein
authors.initials: H
authors.lastname: Attar
authors.forename: Didier
authors.initials: D
authors.lastname: Lièvremont
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Lett
authors.forename: Frédérique
authors.initials: F
authors.lastname: Barbier
authors.forename: Florence
authors.initials: F
authors.lastname: Lagarde
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods*; D000965:Antimony / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018533:Biomass; D002424:Caustics / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013058:Mass Spectrometry; D009994:Osmolar Concentration; D015203:Reproducibility of Results; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D002424:Caustics; D012997:Solvents; D014867:Water; D000965:Antimony